So called Canon.
They're claiming latest L&T plug-in will only work if you're targeting files off a device (ie off original cards) or a virtual drive. Also said that's been true of previous Canon HDSLR model's footage - 5D ii, 7D, etc. Which totally wasn't my experience - for last 2 years been transferring full contents off cards (keeping folder structure intact) onto external drives and opening successfully in L&T from those.
Anyway, still have the cards around so tried to bring in off the original in L&T and still no luck. Again, crashed the app.
Also opened the card in Canon's image browser - does recognize/import the footage but oddly can't read any of the metadata for the clips.
Getting worried, Nick.